Telephone-transmitter



H. A. LARLEE.

TELEPHONE TRANSMITTER.

APPLICATION FILED MN. 3, ms.

Patented Dec. 9, 1919.

Muemor: Herman A. Lair/ea UNITED STATES PATENT OFFICE.

HERMAN A. LARLEE, or YONKERS,

NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEVV YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-TRANSMITTER.

, Specification of Letters Patent.

Patented Dec. 9, 1919.

Application filed January 3, 1916. Serial No. 69,993.

To all whom it may concern.-

Beit known that I, HERMAN ALWARD LAR- LEE, a subject of the King of "Great Britain, residing at Yonkers, in the county of Westchester and State of New. York, have invented certain new and useful Improvements in Telephone-Transmitters, of which ing chamber the following is a full, clear, concise, and exact description. This invention relates to improvements in telephone transmitters.

The object of this inventionis to produce a transmitter structure in which the tendency of the comminuted material to pack is reduced to a'minimum. V In accordance with the general features of this invention, means are provided for changing the physical condition usually present with the flexible diaphragm'after it has been assembled in a transmitter button. This is accomplished by clamping the trans mitter electrode to the diaphragm by means which engage the diaphragmonly at a few widely separated points. The diaphragm may also be secured to the granule-contain in a similar manner. These results may be' obtained by inserting between the flexible diaphragm and the electrode clamping means a washer radial bearing ridges or suitable the diaphragm, and by interposing between the diaphragm and a clamping ring,

by which the diaphragm is secured to the granulecontaining chamber, a separating ring having projections thereonwhich engage and bindthe diaphragm only at a plurality of widely separated points adjacent to its periphery.

In the accompanying drawing,Fi'gure 1 is a detail view, in side sectional elevation, of a transmitter completely assembled inaccordance with this invention; Fig. 2 is a side view partially in perspective of the various parts which enter into the assembly of the transmitter button or granule-containing chamber shown in Fig. 1.

Referring to the drawing, a casingl serves to inclose the working parts of the transmitter and to support a face plate2, which in turn carries a mouthpiece 3. A diaphragm 4: is secured near its periphery to the face plate 2, and a bridgemember 5, also carried by the face plate, serves to support a granule-containingchamber 6. As

having shown in the drawing, the chamber 6 is of circular cup-like form, adapted to receive the transmitter button assembly, which, in this invention, is composed of the following parts. An electrode 9, formed as a disk, is attached to and occupies the bottom of the chamber 6, and on top of this electrode is placed a suitable quantity of comminuted resistance-varying material 10; a lining 8 serves to insulate the granule material 10 from the wall of the chamber. A front or movable electrode 11 is suitably attached to the face of a metal disk 12, which carries centrally on its opposite face a screwthreaded stem 13. The stem 18 is adapted to receive a washer-like diaphragm 14:, pref erably of mica, and in turn a metal washer 15, oneside of which is provided with radially extending bearing ridges 16 faced to rest on the mica diaphragm 14. A threaded nut'l7 next placed on the stem 13 serves to clamp the diaphragm 14 against the rear surface of the electrode backing disk 12.

Thediameter of the electrode 11 and disk 12 is somewhat less than the inside diameter of the chamber 6, andthe diameter of the diaphragni 1A is approximately equal to the outside diameter of the chamber 6' at its rim. Accordingly, when the electrode 11 is placed Within the chamber 6, the diaphragm l4 rests at its periphery on the top of the chamber wall. In this position, a flat ringshaped washer 18, provided on its face with three raisedpoints or feet 19, is seated with the, feet resting near the periphery of the diaphragm 14:, in which position it is clamped by a flanged ringshaped nut 20 adapted to engage the threads provided 011 the outside surface of the chamber wall near its rim.

l The assembled transmitter button is secured in place by passing the stud portion 7 of the chamber 6 through an opening in the bridge member 5, to which it is suitably and rigidly secured in position to permit the head of the nut 17 to rest against the main diaphragm 4:. A spring 21 attached to, but insulated from, the bridge member 5, 'at the binding screw assembly 22, is adapted to engage the flange under the head of the nut 17 and exert pressure to retain this nut in physical contact with the diaphragm 4:- The spring 21 also serves as a conductor in completing the electrical connection of the front electrode 11 with the bindingscrew 22, which also serves as one of the transmitter circuit terminals. The diaphragm 4 is suitably insulated at its periphery from the face plate 2 by the in sulating material 23, and the other terminal of the transmitter is therefore, for con venience, through bridge member 5 to the casing of the transmitter.

This transmitter operates in the wellknown Way, that is, sound waves entering the mouthpiece 3 set up vibrations of the diaphragm 4, and in turn these vibrations are transmitted through the nut 17 and its associated parts to the front electrode 11. The flexibility of the mica diaphragm let permits these vib 'ations to set up reciprocative movement of the electrode 11, to thereby cause variations of pressure and accordingly changes of resistance through the granule material 10.

In the above described embodiment of the presentinvention, the 'aised portions 16 and 19 of the washers 15 and 18 respectively constitute the means by which the characteristic condition of the diaphragm 1a is changed. This change results in a phenommenon with respect to the granule material 10 whereby the tendency of this material to pack is appreciably reduced.

It will be understood that the advantages of this invention may be present when a plain washer or an equivalent thereof is substituted for the washer 15; the washer 18 alone serving to establish the desired characteristic condition of the diaphragm 1 1, and alternately the washer 18 may be dispensed With or a' plain washer substituted therefor,'in this case the washer 15 alone serving to bring about the desired condition of the diaphragm let.

If desired by arranging the relative angular positions of the radial ridges 16 on the washer 15 so that in the assembled structure the extended axes of the ridges pass through the points of contact of the feet 15) of the ring 18 with the diaphragm 14 a greater flexibility of the diaphragm may be obtained than where the lugs 19 engage the diaphragm out of angular coincidence with the extended-axes of the ridges 16.

What is claimed is:

1. In a telephone transmitter, comminuted material, a containing chamber for said comminuted material, electrodes for said ing one of said electrodes to the diaphragm,

and means adapted to limit the engagement of said clamping means to separated portions of said diaphragm.

2. Ina telephone transmitter, comminuted material, a containing chamber for said comminuted material, electrodes for said chamber, a diaphragm adapted to be assembled to carry one of said electrodes and to seal said chamber, and means included in the assembly of said diaphragm to limit the bearing points on said diaphragmv to radially separated sections thereof.

3. In a telephone transmitter, comminuted material, a containing chamber for said comminuted material, electrodes for said chamber, a diaphragm adapted to seal said chamber, clamping meansfor securing said electrodes to said diaphragm, means limiting the engagement of said clamping means to separated points on said diaphragm, means for securing said diaphragm to said casing, andmea-ns for limiting the engage ment of said securing means to separated points on said diaphragmj V V 4. In a telephone transmitter, comminuted material, a containing chamber for said ma terial, electrodes for said chamber, and clamping means' to secure one of said electrodes to said diaphragm; said clamping means including a member having a plurality of spaced radial ridges to engage said diaphragm.

5. In a telephone transmitter, comminuted material, electrodes for said chamber, 21- diaphragm adapted to seal said chamber,clamp ing means to secure oneof said electrodes to said diaphragm and including a; member having a plurality of spaced radial ridges to engage said diaphragm, and a second clamping means to securesaid diaphragm to said chamber and including a member having a plurality of spaced feet to engage said diaphragm at spaced points substantially at the periphery thereof.

In Witness whereof I hereunto subscribe my name this 30th day of December, A. D 1915. i

HERMAN A. LARLEE. 

